Re: [PATCH v1 4/4] vduse: update the vq_info in ioctl

[Jason Wang]

On Wed, Oct 11, 2023 at 2:42 PM Cindy Lu <lulu@xxxxxxxxxx> wrote:
>
> In VDUSE_VQ_GET_INFO, the driver will sync the last_avail_idx
> with reconnect info, After mapping the reconnect pages to userspace
> The userspace App will update the reconnect_time in
> struct vhost_reconnect_vring, If this is not 0 then it means this
> vq is reconnected and will update the last_avail_idx
>
> Signed-off-by: Cindy Lu <lulu@xxxxxxxxxx>
> ---
>  drivers/vdpa/vdpa_user/vduse_dev.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> index 0f15e7ac716b..42e7a90ab74c 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -1213,6 +1213,9 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
>                 struct vduse_vq_info vq_info;
>                 struct vduse_virtqueue *vq;
>                 u32 index;
> +               struct vdpa_reconnect_info *area;
> +               struct vhost_reconnect_vring *vq_reconnect;
> +               struct vhost_reconnect_data *dev_reconnect;
>
>                 ret = -EFAULT;
>                 if (copy_from_user(&vq_info, argp, sizeof(vq_info)))
> @@ -1244,6 +1247,19 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
>
>                 vq_info.ready = vq->ready;
>
> +               area = &dev->reconnect_status;
> +               dev_reconnect = (struct vhost_reconnect_data *)area->vaddr;
> +
> +               area = &vq->reconnect_info;
> +               vq_reconnect = (struct vhost_reconnect_vring *)area->vaddr;
> +               /*check if the vq is reconnect, if yes then update the last_avail_idx*/
> +               if ((vq_reconnect->last_avail_idx !=
> +                    vq_info.split.avail_index) &&
> +                   (dev_reconnect->reconnect_time != 0)) {
> +                       vq_info.split.avail_index =
> +                               vq_reconnect->last_avail_idx;
> +               }

This may work only for split, how about packed? And I wonder when such
synchronization is not done at set_vq_state() but get_vq_info()?

Thanks

> +
>                 ret = -EFAULT;
>                 if (copy_to_user(argp, &vq_info, sizeof(vq_info)))
>                         break;
> --
> 2.34.3
>